How on earth did people travel some ten or twenty years ago I wonder? You know, before cellphones were widespread or even affordable? For fuck's sake, children aren't dumb. Always treating them as if they are results in them not growing into independent adults.

Besides, unaccompanied flights are awesome as a child. I did that once, don't remember how old I was. Flew with the German Lufthansa from my parents to my grandparents. You can't imagine how adult I felt, flying (almost) all alone. I remember the attendants were all friendly and helpful, and the gentleman next to me even swapped his seat with me so I could look out of the window. It was a valuable and memorable experience.

Still doesn't address the key issue which was noone at United cared enough or had the initiative to deal with the problem of a missing child / missed flight situation and left the children unattended.